Semiautomatic transmission



Dec. 23, 1947. B. A. swENNx-:s 2,433,003

` SEMI-AUTOMATIC TRANSMISSION Filed Nov. 15, 1940 2 Sheets-Sheet l Dec. 23, 1947. B. A. swENNEs 2,433,003

SEMI-AUTOMATI C TRANSMISSION Filed NOV. 15,` 1940 2 Sheets-Sheet 2 "WMZ lPatenti-.ti 23, 1,7947

UNITED STATES PATENT OFFICE 2,433,1)03 sEMIAU'roMA'rIc TRANSMISSION Benjamin A. Swennes,` Rockford, Ill., assigner to Borg-Warner Corporation, Chicago, Ill., a corporation of Illinois n Animation November 1s, 1940, serial No. 365,737

`or Vreplace the,`conventional friction clutch. and

three speed gear transmission usedin automo- I ing description when taken together with ,the accompanying drawings in which:

biles. These fluid devices, particularly the kinetic type, possess ,characteristics which .make them highly desirable for such use. Such fluid couplings and torque converters, when used in place of the friction clutch of the conventional transmission, give a very smooth start, absorb vibration and shock, and permit a car to be rolled over obstacles which otherwise would require either a dangerous slipping of a clutch or a sudden applig cation of power which imposes great shock loads V a countershaft type transmission undesirable characteristic is that of' imposing a 25 constant drag upon the driven elementof the I ency-.of the vehicle to creep. It has been proposed to remove thisundesirable dragby forcibly stopping the driven element of the fluid drive. This of course does remove the drag insofar as the fluid device is concerned, butV if the driven element is forcibly stopped while the vehicle is still in motion, the inertia of the vehicle would impose an equally great load upon the `gears and clutches` which would react against the stopping means and render gear shifting impossible.

The principal object of this invention is to provide a transmission of the fluid drive type in which the drag imposed by the fluid device is removed and in addition the load of the vehicle is relieved from the elements between'the iluid de- Yvice and the rear Wheels.

Another object of this invention is to provi ve a satisfactory control device for a transmission employing the load relieving means of this invention. y

A feature of this invention is asupport for a transmission which is insulated from the chassis of the vehicle in which it is installed to avoid the l transmission of gear noises thereto.

Fig. 1 is a section through the transmission;

Fig. 2 is a section taken along lines 2-2 of Fig. 1; and

Fig. 3 is a. section of the transmission taken along the lines 3?-3 of Fig. 1.

Referring now to the drawings for a. detailed description of the invention, the transmission is comprised of a drive shaft -IIl to which is secured la fluid coupling II of the Fottinger type which,

in turn,` drives an intermediate shaft I2.

Said intermediate shaft I2 passes rearwardly to I3 changes the speed and torque ratio of the drive in intermediate shaft I2 and then transmits the changed drive to driven shaft I4. I

Fluid coupling II is comprised of a, flywheel housing I5 to which is secured a vaned driving rotor I8. Opposite rotor IB is a driven rotor l'I of the vaned type which is secured to `a flanged hub I8 splined to intermediate shaft I2. Appropriate seals I9 and 2li between iiywheelv housing I5 and hub I 8 retain the driving fluid within housing I5.

Transmission I3 is comprised of a drive gear 2| formed on the end of intermediate shaft I2 which engagesa first gearA 22 of a gear cluster 23. Said gear cluster 23 is free to rotate about a countershaft 24. A second gear 25 on gear cluster 23 is constantly in mesh with a gear 26 which is rotatably mounted on driven shaft Il by means of an over-running clutch 2l. A third gear 28 on gear cluster 23 is adapted to engagea slidable gear 29 coupled by means of splines 85 to driven shaft Il, and a fourth gear 30 on gear cluster 23 is adapted to drive gear 29 through the intermediary of an idler (not shown) to establish a, reverse drive.

Driven shaft I4 can be coupled directly to intermediate shaft I2 by means of a. conventional synchronizer type jaw clutch 3| which has a slidable collar 32 provided with internal teeth adapted to engage external teeth 33 on gear 2l and thereby connect them with a hub member 34 on driven shaft. I4. Overrunning clutch 21 is provided with a hub member I8 which has teeth` 'I9 adapted to be engaged by collar 32 to connect hub member 'I8 with driven shaft I4. (I

For purposes' of illustration, this invention will 4 be described as appliedto transmission i3 when the latter is equipped for semi-automatic operation. It will be noted that the 4gear combinationy I is essentially that of an ordinary three speed and reverse` countershaft type transmission wherein invention will become apparent from the followa sliding gear is used to establish low or reverse which and a synchronizer is used to establish second speed and direct drive. 29 is in the right hand position (Fig. 1) so as to engage the reverse idler, the transmission is conditioned for reverse. In neutral, sliding gear 29 is positioned mid-way between gears 30 and 29 so as to be free of cluster gears 23. For low speed forward, sliding gear 29 is engaged with gear 28 on cluster 23. Second speed is obtained by sliding gear 29 to its neutral position and moving collar 32 of synchronizer 3I to the right so as to connect hub member 19 of overrunning clutch 21 with' driven shaft I4. Thisestablishes a drive between gear 25 and gear 26 through overrunning clutch 21 and synchronizer 3l to driven shaft I4. For direct drive, collar 32 of synchronizer 3I is moved to the left so as to engage intermediate shaft I2 directly with driven shaft I4.

It will be apparent that if gear 29 is left in its neutral position and synchronizer 3| is properly operated 'the transmission may be used as a simple two-speed automatic transmission if desired. The controls for such a two-speed transmission are shown schematically and comprise an electrical governor 35 which is driven from driven shaft I4 by means of suitable gearing 36 so that the governor is responsive to the speed of the vehicle. Electrically associated with the governor 35 is a suitable solenoid 31 having an armature 36 which is adapted to engage collar 32 of synchronizer 3i. Current for operating solenoid 31 may be obtained from a battery 39 or other suitable source of electrical energy., Solenoid 31 is so constructed that below a given speed of say twelve miles per hour, synchronizer collar 32 will be in the right hand position so as to establish and maintain-second speed drive. Above twelve miles per hour armature 39 will be moved to the left` to engage intermediate shaft I2 directly to establish direct drive. If desired, a vacuum controlled switch 49 may be inserted in the circuit between governor 35 and solenoid 31 to delay the operation of solenoid 31 if for any reason the torque load is heavy and low speed is desired. In this 'way the Speed at which solenoid 31 will become operative may be made higher at the will of the operator. The 'shift to direct will become effective when the operator releases the accelerator and a high vacuum is created in the intake manifold of the engine.

Sliding gear 29 requires that cooperating sets of teeth be synchronized and meshed. The meshing cannot take place satisfactorily while relative rotation exists, or, if the teeth are alreadyin mesh, if a load is imposed on the teeth. Fluid coupling II is continuously driven from drive shaft I0, and since the coupling transmits torque as a function of the speed of shaft III, it will impose a slight, but nevertheless appreciable, torque. on intermediate shaft I2 and gear cluster 23 when the vehicle engine is idling, and this torque renders difllcult the engagement of sliding gear 29 with gears 25 or 30. Accordingly, a. brake 4I is provided for driven element I1 of fluid coupling I I. The brake comprises a drum 42 splined to intermediate shaft I2 so as to be rotatable therewith, and a brake band 43 which is shown more clearly in Fig. 2. Said brake band 43 is provided with lugs 44 and 45 by which the band is operated. Lug 44 constitutes the reaction lug and reacts against a bell crank 46 whichin turn reacts against an abutment 41 in bell housing 49 which surrounds fluid coupling II. The reaction against abutment 41 is taken through a spring 49 or other resilient means so that rela- Thus when sliding gear`- tive motion is permitted between bell crank 46 and the abutment up to a certain point and beyond that point spring 49 is no longer effective. For this reason bell crank 46 is provided with a pin 50 which serves to support one end of the spring 49, and abutment 41 is provided with a similar pinv 5I which serves to support the opposite end of spring 49. Said pins 50 and 5I engage before spring 49 is fully compressed.

Lug 45 is connected by means of a rod 52 to an operating piston 53 in a cylinder 54. A conduit 55 connects cylinder 54 with cylinder 56 of the service brake pedal 51.

It is undesirable to have brake 4I applied every time service brake 51 is operated since on many occasions a driver may wish merely to slow down and not come to a stop and he would then be using brake 4I to stop the vehicle in addition to or instead of the regular service brakes. It is preferred to operate brake 4I only when making a shift in the transmission and since these shifts, particularly the shift between forward and reverse, are made when the car is standing still it is preferred to operate brake 4I only when the vehicle is not in motion or is coming to a stop. For this reason a valve 58 is interposed in the conduit 55 leading from brake cylinder 56 to cut ofi cylinder 54 from the brake system at al1 times except when it is necessary to operate brake 4I. The control for valve 59 may comprise a solenoid 59 the circuit to which is controlled in turn by shiftv lever 60 at the steering wheel 6I. Lever 60 is pivoted at 62 and is provided at its inner end with a pair of contacts 63 and 63a which are in the circuit to the solenoid 59. Shift lever 60 may be of standard type employed with three-speed transmissions and as such has two planes of movement, one above the other. The upper plane is used for reverse and low speed and the lower one is used for second and direct. In the present transmission the shift from second to direct and back to second is made automatically and the second speed position may be omitted. When in neutral. lever 60 rests in the lower plane. Contacts 63 and 63a are so arranged that when lever 69 is in neutral position in the lower plane, the circuit through solenoid 59 is broken, but when lever 60 is raised to its upper plane preparatory to shifting either to low or reverse, the circuit will be completed to operate solenoid 59 and open valve 56 to permit pressure to be transmitted to cylinder 54 from brake cylinder 56. Before completing the shift to either of the ratios permitted, the circuit will be broken and valve 58 will be restored to its closed position to prevent the transmission of fluid pressure to cylinder 54. A ball check valve 64 permits any fiuid under pressure trapped in cylinder 54 to escape around valve 58 if the valve should be in its closed position and brake pressure is relieved, otherwise the car would be unable to move, despite the release of the service brakes.

It will be apparent that with brake 4I applied and transmission I 3 in low gear, that is, with gear 29 engaging gear 28, it would be possible to halt the carin such a fashion as to impose a load on driven shaft I4 which in turn would impose a load on the gear train up to and including brake 4I. With brake 4I applied however, this load remains on the gear teeth and makes it substantially imv possible to shift gear 29. Such a condition would culty the novel mechanism hereinafter `described isemployed. V t, v

Countershaft 24 is mounted in a frame il which is free to rotate about shaft I4. Suitable bearings 66 are provided for this purpose. Surrounding frame 65 is a casing 61 which is closed o!! at the rear by plate B8. Said plate 88 is yprovided with a pair of abutments 69 whichare; in the path of travel of frame 65. Abutments 69 are so spaced as to permit a limited amount of oscillation of frame 65 about shaft I4. To avoid excessive noise the inner surfaces of abutments 60 are provided withblocks of rubber 1i! vulcanized to the abutments.

Under ordinary conditions, frame 85 is held against oscillation in either direction by lmeans of a pin 1| which extends into an aperture 12 in frame 65. Said pin 1I passes through an opening 13 in the forward closure plate 14 `oi' housing 61. Its forward end is pivotally connected by means of a lost motion connection 15 to an arm 1I of bell crank `46. Bell crank 46 is in turn pivoted in a lug 11 on closure member 14.

Thus when brake 4I is operated, the pressure in cylinder 54 is transmitted to reaction lug 44 on brake band 43 and thence to bell crank 48 is vulcanized ameta'nnersl. with the enginel l 41 makes it possible touse a much lighter construction" everywhere except in closure plate 14 which takes the reaction of brake 4i. Thus the greaterportion off casing 01 can be made of very light 'castings or from aheavier `gauge sheet metal. y i j This invention is applicable generally to any ltransmission having a posltlvecoupling of some kind in the torque transmitting circuit. In the transmission described, the coupling is comprised of splines 85 which transmit the drive from gear 29 to shaftv I4. In other transmissions it .may be a jaw clutch, similar to that connecting intermediate shaft I2 and driven shaft I4. When applied to a transmission of the type described a very inexpensive twofspee'd automatic transmission rewhich is then rotated about its pivot 11. This rotating,i movement is transmitted through arm 'IB and pivotal connection 15 to pin 1I to withdraw said pin from aperture 12, thereby freeing frame B5. If at the time brake 4I is operated a load exists on shaft I4, this torque load will be transmitted through gear 29 to gear 28.v It will be noted at this point that gear 28 and its associated gear 22 form in eii'ect-a pair of planet gears which are rotatable freely, within the limits provided by abutments 69. about shafts' I4 and suits which is satisfactory for the greater portion `of the driving conditions usually encountered.

. `The governor automaticallyshifts synchroniser I2. Due to the difference in diameters between gears 2| and 29 the torque load on gear 20 will result in a planetary vmovement of cluster gear 23 and its associated framet about intermediate shaft I2 and driven shaft I4. This rotation will continue until either an abutment is struck or the torque load is relieved. If frame BI strikes an abutment 69 before'the torque load is relieved, the operator merely releases the brake by releasing service brake pedal 51 which thereby interposes an opposing torque due to the drag existing in fluid coupling il. This opposing torque may be made to balance the remaining load inthe gears, and when such a balance is established, gear 29 may then be moved freely out of engagement with gear 28. Should the vehicle be so situated that the smallest movement thereof would be inexpedient or hazardous, the emergency brake may be substituted for the service brake while the latter is released. A, y

Substantially the same conditions'obt'ain with respect to the reverse gear connection, and the torque relieving means described above is equally as effective for getting outyof reverse asv it is for getting out of-low.

The foregoing construction causes all radial l thrusts between the gears to be taken by frame and the loads between frame 6B and case l1 are therefore principally lthose imposed yby the dead weight of the transmission. This renders possible the use of resilient mountings 80 and 80a between frame 65 and casing 81 which will mate- 3-I to whatefverratio is called for by the speed of the vehicle, theY overrunning clutch rendering the shifting to and from second speed easy, and the slip characteristic ofthe fluid coupling relieving the direct ldrive clutch; of torque vto permit the shift out ofdirect at low speeds. The shift into direct is, of course,V effected upon the torque reversalA resulting from the release of the accelerator pedal andis thereforelreadily achieved. For diillcult conditions in which the two auto#V matic speeds are' notv adequate. the manually operated low speed is available, the means described above rendering thebp'eration of the low speed controls easy. `I A It isunders'tood that the foregoing description is merely illustrative `of .aj preferred embodiment of theinventionand Ithat the'scope of the invention therefore is not to be limited thereto but is tc be determined by the appended claims.

I claim: t

l. A transmission comprising a drive shaft, a driven' shaft, change speedge'aring connected between the shafts, `said gearing including a positive coupling, and `a lco'untershaft, means for arresting the rotation ofone of the shafts, a supporting-,means for the countershaft adapted to move the 'countershaftj a limited distance, and means normally fixing the countershaft, said fixing means being releasable in timed relation to the arrestingfof the vsaidone of the shafts. whereby to relieve the vpositive coupling of load.

2. A transmission comprising a drive shaft, a hydraulic coupling deviceconnected to the drive shaft, said coupling having driven and driving rotors, a 'driven shaft, change speed gearing connected betweenthedriven rotor and the driven shaft, said gearing .including a positive coupling and a countershaft. means for arresting the driven rotor while the driving rotor is rotating. a supporting means for the countershaft adapted to move the countershaft through a limited distance, and means normally fixing the countershaft, said fixingv means being releasable in timed relation to the arresting ofthe driven rotor, whereby to relieve the positive coupling vof load.

3. A transmission comprising' a drive shaft, a

driven shaft, change speed gearing between said shafts, said gearing including a sliding gear, a countershaft, a support for the countershaft rotatably mounted with respect to the driving and driven shafts, means for fixing the countershaft against rotation, a brake for the drive shaft, means connecting the brake with the xing means and adapted to release the countershaft when the brake is applied, stops limiting the rotational movement of the countershaft, and manual means for operating the brake, said countershaft when released being capable of rotating in the direction of relieving any torque that might exist on the sliding gear as a result of the application of the brake.

4. A transmission for an automotive vehicle comprising a drive shaft, a driven shaft, change speed gearing between said shafts, said gearing including a positive coupling means, a countershaft, a support for the countershaft rotatably mounted with respect to the driving and driven shafts, means for fixing the countershaft against rotation, a brake for the drive shaft, means connecting the brake with the fixing means and adapted to release the countershaft when the brake is applied, stops limiting the rotational movement of the countershaft, a service brake for the vehicle, and connections between the service brake and the drive shaft brake whereby to operate the latter from the former, said countershaft being capable of rotating in the direction of relieving any torque that might exist in the positive coupling as a result of the operation of the driving shaft brake.

5. A transmissionr as described in Vclaim 4, a control for the positive coupling, and means for preventing the operation of the driving shaft brake except when the control for the positive coupling is operated.

6. A transmission for an automotive vehicle comprising a drive shaft, a driven shaft, a hydraulic coupling having a drive rotor connected to the drive shaft and a driven rotor, a change speed mechanism connected to the driven rotor and to the driven shaft, a brake for the driven rotor, means for operating the rotor brake, automatic means for controlling a portion of the 'change speed mechanism, manual means for controlling another portion of the change speed mechanism, said manual controlling means also controlling the rotor brake, a countershaft in the change speed mechanism adapted for limited rotational movement about the axes of the drive and driven shafts to relieve the manually operated portionof the mechanism of load torque, and means for holding the countershaft against such rotational movement, said means being controlled by the rotor brake.

7. A transmission for an automotive vehicle as described in claim 6, a service brake for the vehicle, and a, connection between the service brake and rotor brake whereby to operate the latter from the former.

8. In a transmission, the combination of a drive shaft, a driven shaft, the axes -of said shafts lying on a common line, means for completing a power train between said shafts and including elements adapted to positively interengage,

means for arresting one of said shafts, and means effective for permitting rotation of one of said interengageable elements in either direction in an orbit about an axis substantially coinciding with the axes of said shafts when said arresting means is operative whereby said elements may be easily engaged or disengaged.

9. Apower transmission system comprising a source of power, a load, a speed changing mechanism including elements adapted to positively interengage for completing a power train through the mechanism, a connection between said speed changing mechanism and said source of power, a connection between said speed changing mechanism and said load, the axes of rotation of said two connections lying on a common line, means for Iarresting one of the said connections, and means effective for permitting rotation of one of said interengageable elements in either direction in an orbit about an axis substantially coinciding with the axes of rotation of said connections when said arresting means is operative whereby said elements may be freely engaged or disengaged.

l0. A transmission comprising a hydrodynamic torque transmitting device, a drive shaft connected with said device to be driven thereby, said hydrodynamic device constantly applying torque to said drive shaft, a driven shaft, gearing connected between said shafts and including elements adapted to be positively interengaged for completing a gear train between the shafts, said gearing including a reaction element normally held fixed for establishing said gear train, means for arresting said drive shaft, and means for releasing said reaction element when said arresting means is operative whereby to relieve said elements when interengaged from torque to facilitate their disengagement.

1l. A transmission comprising a drive shaft, a drivenshaft, means for arresting the rotation of one of the shafts, change speed gearing connected between said shafts, said gearing including positive interengaging elements and a countershaft, a movable support for the countershaft, and means fixing said countershaft support for completing a power train through said gearing, said fixing means being releasable for relieving the positive interengaging elements of load.

12. A transmission comprising a drive shaft, a driven shaft, means for arresting the rotation of one of the shafts, change speed gearing connected between said shafts, said gearing including positive'interengaging elements and a countershaft, a movable supporting means for the countershaft, and means normally fixing the countershaft supporting means for completing a power train through said gearing, said fixing means being releasable in timed relation to the arresting of the said one of the shafts, whereby to relieve the positive interengaging elements of load.

13. A transmission comprising a hydrodynamic torque transmitting device, a drive shaft connected to be driven by said device, said hydrodynamic device' constantly applying torque to said drive shaft, a driven shaft, the axes of rotation of said drive and driven shafts lying on a common line, a speed change mechanism connected between said shafts,r said mechanism including elements adapted to interengage positively for completing a power train through the mechanism, means for arresting said drive shaft, and means effective for permitting rotation of one of said interengageable elements in either direction in an orbit about an axis substantially coinciding with the axes of said shafts when said arresting means is operative whereby said elements may be freely engaged or disengaged.

14. Apower transmission system comprising a source of power, a load, a hydrodynamic torque transmitting device connected to be driven by 9 said source of power, a drive shaft connected to be driven by said device, said hydrodynamic device constantly supplying torque to said drive shaft, a driven shaft connected to drive said load,y

said coupling means is engaged, a brake for said drive shaft, said coupling means when disengaged allowing rotation of one of said interengageable elements in either direction in an orbit about an axis substantially coinciding with the axes of said shafts when said brake is engaged, and means for making said brake effective and for thereafter disengaging saidcoupling means while said brake is operative whereby said elements may be freely engaged or disengaged.

15. A transmission comprising a hydrodynamic torque transmitting device, a drive shaft connected with said device to be driven thereby, said hydrodynamic device constantly applying torque to said drive shaft, a ,driven shaft, gearing connected between said shafts and including elements adapted to be positively interengaged for completing a gear train between the shafts, said gearing including a reaction element normally held fixed fory establishing said gear train, means for arresting said drive shaft, and means operated by said arresting means for releasing said reaction element when said arresting means is rendered operative whereby to relieve said elements when interengaged from torque .to facili#` tate their disengagement.

BENJAMIN A. SWENNES.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,230,050 Nutt Jan. 28, 1941 2,237,433 Hofmann, Jr Apr, 8, 1941 2,237,958 Hansen et al. Apr. 8, 1941 1,978,172 Sinclair Oct. 23, 1934 2,104,605 Boldt-; Jan. 4,1 1938 2,258,475 Sinclair -e"- Oct. 7,' 1941 2,247,714 Peterson et al July 1, 1941 2,203,177 Patterson June 4, 1940 1,969,561 i Keller Aug. 7, 1934 2,084,219 Salemi June 15, 1937 1,541,240 Barkeij June 9, 1925 2,108,986 Klimek Feb. 22, 1938 y2,256,960 Neracher et al. Sept. 23, 1941 2,082,581 Niep June 1, 1937 2,019,745 Swennes Nov. 5, 1935 1,689,245

Klimek T Oct. 30, 1928 

